The present invention relates to a capsule filling apparatus, and more particularly to a capsule filling apparatus which can be precisely controlled to prevent insufficient or excessive filling of powder into the capsules.
Generally, a capsule includes a hollow container and a cap which has an inner diameter slightly larger than an outer diameter of the container. Different types and doses of medicine powder may be dispensed and filled into the capsule with a capsule filling apparatus.
When using a conventional capsule filling apparatus to fill capsules, the caps of the capsules must first be separated from the containers and medicine powder is filled into the containers with a manually controlled powder filling mechanism. More specifically, the containers with the caps temporarily removed are manually pulled to a filling area for filling medicine powder into the containers. In the conventional capsule filling apparatus, capsules to be filled are positioned on capsule holding means on which multiple rows of holes are arranged in rows side by side to each contain an empty capsule waiting for filling with powder by an operator. The operator tends to fill insufficient or excessive powder into different capsules due to tiredness caused by operation for a long time, making the filled capsules defective products containing insufficient or excessive dosage of medicine powder. This is, of course, undesirable and not acceptable.
FIG. 1 illustrates a conventional capsule filling apparatus 10 in which a capsule positioning mechanism 11, a powder filling mechanism 12, and an assembling mechanism 13 are included. Disc-shaped capsule holding means 14, 15 are provided in the apparatus 10 corresponding to the capsule positioning mechanism 11 and the powder filling mechanism 12, respectively. A plurality of holes 141, 151 are regularly arranged in multiple rows extending from inner to outer side on the capsule holding means 14, 15, respectively, to each receive an empty capsule therein. The capsule positioning mechanism 11 positions empty capsules into the holes 141 on the capsule holding means 14. Vacuum suction is used to suck lower containers of the capsules from the upper caps. Then, the capsule holding means 14 is moved to the powder filling mechanism 12, so that medicine powder is filled into the lower containers. FIG. 2 schematically illustrates steps A to D included in the conventional capsule filling apparatus to fill the capsules. In step A of FIG. 2, the capsule positioning mechanism 11 sends empty capsules 16 into holes 141 on the capsule holding means 14 which is formed from an upper part 142 and a lower part 143. A portion of each hole 141 located in the upper part 142 of the capsule holding means 14 has a diameter larger than that of another portion 144 of each hole 141 located in the lower part 143 of the capsule holding means 14. When the empty capsules 16 are positioned in the holes 14, the caps 161 of the capsules having larger diameter are located in the large-diameter upper holes 141 while the containers of the capsules 16 having smaller diameter are located in the small-diameter lower holes 144. A suction hole 145 having a reduced diameter smaller than that of the lower hole 144 is formed at a bottom of each lower hole 144. Suction is provided by a vacuum source (not shown) to suck the containers of the capsules 16 via the suction holes 145, so that the containers of the capsules are sucked to a lower position in the lower holes 144, as shown in the Step B. At this point, the capsule holding means 14 is moved to the powder filling mechanism 12 and will be referred to as capsule holding means 15 to conveniently distinguish it from the capsule holding means 14 in the capsule positioning mechanism 11. In the powder filling mechanism 12, the upper part 152 (originally 142) of the capsule holding means 15 is removed from the lower part 153 (originally 143) and powder 121 is filled into the empty containers of the capsules 16 in the small-diameter lower holes 154 (originally 144) by the power filling mechanism 12, as shown in the Step C. The lower part 153 and the upper part 152 are then moved to the assembling mechanism 13 to be assembled again, as shown in the Step D, so that the containers of the capsules 16 filled with medicine powder are covered by the caps 161.
In the above-described conventional capsule filling apparatus 10, the capsule holding means 15 is manually controlled through a foot switch 17, as shown in FIG. 1, to rotate row by row in an intermittent manner. And, the powder filling mechanism 12 is manually pulled to locate above the capsule holding means 15 to fill powder 121 into individual capsules. As a result, the capsule holding means 15 is not always precisely located below the powder filling mechanism 12 to permit each capsule to receive accurate dosage of medicine powder. Moreover, the operator tends to fill incorrect amount of powder into the capsules due to tiredness caused by long time of work. Defective capsules with insufficient or excessive dosage are therefore frequently produced.